The issues was raised during a phone call between Iranian Foreign Minister Manouchehr Mottaki and his Japanese counterpart Hirofumi Nakasone held at Tehran's request, the Japanese foreign ministry said.
"Foreign Minister Mottaki said Iran expects Japan to play a role in the efforts to end the Israeli attacks on the Gaza Strip immediately," the ministry said in a statement.
Nakasone told Mottaki that Japan would "continue making proactive efforts on this issue as a member of the UN Security Council."
Nakasone also spoke to his Italian counterpart, Franco Frattini, separately by phone and agreed to cooperate among Group of Eight nations in calling for a truce in Gaza, the Tokyo foreign ministry said.
Japan, currently the chairman of the G8 group of wealthy nations, has sought a larger role in the Middle East. Tokyo last week announced it would provide $10 million in emergency humanitarian aid for the Gaza Strip.
Japanese Prime Minister Taro Aso has held separate telephone talks with Israeli Prime Minister Ehud Olmert and Mahmoud Abbas, president of the self-ruled Palestinian Authority, which of course has little, if at all, control over Gaza.
Israel waged war on the Gaza Strip on December 27 and began a "long-term" ground offensive on the Palestinian territory last Saturday.
Thus far, the Israeli aggression has killed 804 Palestinians and injured 3310 - a large number of the casualties are civilians.